The present invention provides a blood marker for renal cancer, more specifically, a blood marker that can be practically used for clinical diagnosis of renal cancer. The present invention also provides a blood marker that can be practically used for follow-up after treatment such as surgery and during treatment such as medication for renal cancer. A blood marker for renal cancer selected from the group consisting of Galectin-1, Galectin-3, and α-enolase. Galectin-1 and/or Galectin-3 as a blood marker for renal cancer for use in an examination performed before diagnostic imaging. α-Enolase as a blood marker for renal cancer for use in monitoring during and/or after treatment for renal cancer.